There is need for impressing conductors and electrical cabling of a wide variety of sizes and types with distinctive symbols and markings useful in identifying and imparting useful information to installers and service technicians. Many proposals have been made heretofore to meet these requirements but the ever-increasing advances in technology impose ever-increasing and taxing demands on the available coding equipment. Modern equipment for extruding insulation jacketing onto conductors is capable of processing conductors at speeds up to and in excess of 2,000 feet per minute. Desirably freshly applied insulation is quite warm and at a favorable temperature for quickly drying films of fluid applied thereto as coding symbols. However, coding equipment available prior to this invention has numerous shortcomings including, in particular, its unsuitability of operating satisfactorily at the conducting insulating speeds of modern extruding equipment. A particularly perplexing problem characteristic of prior wire coding devices when operating at higher speeds involves unsatisfactory and inadequate means for collecting and controlling excess coding fluid. Additionally, presently available equipment capable of simultaneously applying coding in more than one color utilizes a rotating head supporting three rollers operating to apply a like number of continuous stripes to a conductor. Such equipment is relatively expensive and suitable for use with larger diameter conductors. Simpler and less expensive equipment heretofore proposed is limited to operation at speeds of approximately 700 feet per minute and to the use of a single color. Moreover, prior constructions have been complex and costly to manufacture, service and maintain. Cleaning operations are time consuming and difficult.
The following patents typify prior coding equipment: Schake et al U.S. Pat. Nos. 1,958,717; Hargreaves et al 2,344,610; Lowe 2,739,528; Weber 2,836,146; Gillies 2,898,848, 2,898,849; Gemelli 2,934,005, 3,136,242; Burns 3,043,721; Gillies 3,225,688; Wilcocks 3,280,729; Gartside 3,635,153; Rundell 3,709,143; Brown 3,739,717.